I don't feel Jones goes into a shell in his prime when he gets hit. And that is of course, if you can actually hit him lol. I see your point a bit, just happen to see it as being unlikely.
Well it was rare to even hit the guy in his prime but when he was tested his game plan changed he became much less willing to trade in pockets and instead utilized his lighting reflexes to pop in and out of the action. This of course worked well for him but as time past so did his abililty to keep this game plan working effectively. One fight you can review is his fight with Lou DeValle. Roy was dismatling Lou until he was hit and charged with a flash knock down after this Roy traded less and fought a different fight a less busy one but effective enough to coast through the bout.
I guess a "shell" is the wrong choice of words and I apologize, I guess his in the pocket output dwindled a bit but of course not enough for the normal human eye to detect. :yep